Firearm and cartridge therefor



Nov. 14, 1961 D. A. JOHNSON FIREARM AND CARTRIDGE THEREFOR Filed June15, 1960 INVENTOR. Q/q. c/oH/vso/v jfflli. 4Z4

3,008,258 FIREARM AND CARTRIDGE THEREFQR David A. Johnson, Box 66,Malin, Oreg. Filed June 15, 1960, Ser. No. 36,225 2 Claims. (CI. 4214)This invention relates to a novel construction of cartridge chamber andbolt and to a novel construction of cartridge for use therewith, wherebythe cartridge chamber is sealed by the forward end of the bolt due tothe pressure created by the firing of the cartridge, to prevent escapeof the expanding gases rearwardly from the cartridge chamber untilpressure in the chamber is released by' the projectile of the cartridgeleaving the muzzle of the barrel.

Another object of the invention is to provide a novel construction ofcartridge wherein no case is provided and the propellant charge andprimer are completely consumed by the firing of the cartridge.

Still a further object of the invention is to provide an improvedfirearm and cartridge therefor whereby the need for an extractor andejector are eliminated.

Still a further object of the invention is to provide a firearm ofgreatly simplified construction wherein the likelihood of malfunctioningwill be reduced to a minimum by elimination of the extractor and ejectorand the need for an ejector opening.

Still a further object of the invention is to provide a firearm having anovel construction of bolt or breechblock including a part which iscapable of being expanded by the pressure generated by the explodedpropellant charge of the cartridge for sealing the cartridge chamberuntil the projectile of the cartridge has left the barrel muzzle.

Various other objects and advantages of the invention will hereinafterbecome more fully apparent from the following description of thedrawing, illustrating presently preferred embodiments thereof, andwherein:

FIGURE 1 is a longitudinal, substantially central sectional view, partlyin elevation, of a portion of a firearm constructed in accordance withthe invention and shown containing the improved cartridge;

FIGURE 2 is a cross sectional view thereof, taken substantially along aplane as indicated by the line 2-2 of FIGURE 1;

FIGURE 3 is a side elevational view of the cartridge;

FIGURE 4 is a longitudinal, substantially central section-al view of therear end of the barrel, and

FIGURE 5 is a fragmentary substantially central longitudinal sectionalView, partly in elevation, of a sli htly modified form of the firearm.

Referring more specifically to the drawing and first with reference tothe form of the invention as illustrated in FIGURES 1 to 4, a portion ofa firearm as shown therein is designated generally 7 and includes therear portion of a firearm barrel, designated generally 8, and theforward portion of a bolt, designated generally 9.

The barrel 8 is provided with a cartridge chamber 10 the forward end ofwhich opens into a barrel bore 11 and the rear end of which opens into acavity 12 which is formed in and opens outwardly of the rear end of thebarrel 8 and which is of larger diameter than the chamber 10.

The bolt 9 is of the type having reciprocating move ment axially thereofand of the barrel 8 and may be of the blow-back type as used insubmachine guns. The head portion or forward end 13 of the bolt 9 has aforwardly opening cavity 14 therein providing an annular skirt 15,constituting the wall surrounding said cavity 14. The bolt head 13 has aportion 16 extending into the cavity 14 and which is of a diametersubstantially less than the diameter of the cavity. The bolt portion3,08,Z58 Patented Nov. 14-, 1961 16 has a substantially flat forwardface 17 from which extends a tit or projection 18. The forward face 17is set back with respect to the forward end of the skirt 15 so that thetit 18 is contained within the cavity or socket 14.

If desired and as illustrated in FIGURE 1, the bolt head 13 may bedetachable from the forward end of the body 19 of the bolt 9, as bybeing provided with an extension 20 at its rear end which is threadedlysecured in a forwardly opening socket 21 of the bolt body 19.

The improved cartridge, designated generally 22 and illustrated inFIGURES l and 3, consists of a formed propellant or explosive charge 23having a forwardly opening socket 24 in the forward end thereof in whichthe rear end portion of a conventional projectile 25 is seated andanchored. The rear end of the propellant charge 23 is provided with asmall rearwardly opening socket 2d containing a primer 27. Thepercussion composition, constituting the primer 27, is likewise formedso that no case is required and the propellant body 23 provides theanvil for the primer 27.

Any suitable mechanism, not disclosed, constituting no part of thepresent invention, may be utilized for seating the cartridge 22 in thechamber 10 and for there after releasing the bolt 9 and to effectforward movement of the bolt from left to right of FIGURE 1 and towardits position of FIGURE 1. The external diameter of the bolt head 13, orat least the skirt 15 thereof, is slightly less than the diameter of thecavity 12. The clearance between the skirt 15 and the annular wall ofthe cavity 12 is exaggerated for clarity' in FIGURE 1. The tit 13 isdisposed to align with the primer 27 so that as the bolt Q approachesits forwardmost position and when it has reached its position of FIGURE1, the tit 18 will strike and detonate the primer 27 to ignite thepropellant charge 23 as the forward end of the skirt 15 reaches theinner end or bed of the cavity 12, or slightly beyond its position ofFIGURE 1. The pressure from the expanding gases of the ignitedpropellant body 23 will cause the skirt 15 to expand into tightengagement with the surrounding wall of the cavity 12 to seal the rearend of the cartridge chamber 10, so that the pressure of the expandinggases will propel the projectile 25 forwardly through the bore 11. Asthe projectile 25 leaves the barrel muzzle, not shown, pressure in thechamber 10 is released and the skirt 15 is sufiiciently elastic toenable it to contract to its original size as shown in FIGURE 1, so thatthe skirt can be readily withdrawn from the cavity 12 as the bolt isretracted. The propellant body 23 and primer 27 will be completelyconsumed, leaving nothing to be extracted from the chamber 10 orthereafter ejected from the firearm so that the chamber 10 will be readyto receive another cartridge 22.

It will be understood that the size and shape of the propellant body 23may vary and this likewise applies to the chamber 10. The length of thecartridge 22 may likewise vary, since the length of the bolt headportion 16 may be varied or said portion may be omitted so that the tit18 projects from the bed of the cavity or socket 14. It will also beapparent that the bolt may be provided with a conventional firing pin,in lieu of the tit 18, and which can be released and advanced to strikethe primer 27 after the bolt has reached a battery position.

FIGURE 5 illustrates a slightly modified form of the barrel and bolt andwherein the cavity 12' of the barrel 8' is inwardly tapered and theskirt 15' is similarly tapered toward its extremity. The taperedconstruction of FIG- URE 5 allows for expansion due to heat and whichmight otherwise interfere with retraction of the bolt 9' after repeatedfiring.

Various other modifications and changes are contemplated and may beresorted to, without departing from the function or scope of theinvention as hereinafter defined by the appended claims.

I claim as my invention: 1. In combination with a firearm cartridgecomprising a formed propellant charge body having a rear end containinga primer and a projectile secured to and projecting from a forward endof said propellant body; a fire-- 7 said cavity and defining aforwardly'opening socket in including an annular skirt sized to slidablyengage in" said cavity and defining a forwardly opening socket in thebolt, and means carried by said bolt and disposed in said socket toengage and detonate the cartridge primer for igniting said propellantbody when said skirt is contained in the-barrel cavity, said skirt beingexpanded by the pressure of the expanding gases within said socket intosealing engagement with the surrounding wall of the cavity for sealingthe rear end of the cartridge chamber,

until the projectile has been propelled'from the barrel by the expandinggases generated bythe propellant body, said skirt being externallytapered toward its extremity, and said barrel cavity beinginwardlytapered to conformably receive the skirt.

2. In combination with a firearm cartridge comprising" a formedpropellant charge body having a rear end containing a primer and aprojectile secured to and projecting from a forward end of saidpropellant body; a firearm barrel having a'charnber for receiving saidcartridge, said barrel having a cavity opening outwardly ofa rear endthereof and into which the rear end of the cartridge chamber opens, saidcavity being larger in cross section than the cartridge chamber, a bolthaving a forward' end slidably movable into, said cavity, "saidforwardbolt end including an annular skirt sizedto slidably'engage inthe bolt, and means carried by said bolt and disposed in said socket toengage and detonate the cartridge primer for igniting said propellantbody' when said skirt is contained in the barrel cavity, said 'skirtbeing expanded by the pressure of the expanding gases within said socketinto sealing engagement with the surrounding Wall of the cavity forsealing the rear-end ofthe cartridge chamber 7 until the projectilehasrbeenprop'elled from-the barrel by the expanding gasesv generated bythe'propellant body, said 'bolthaving a portion projecting forwardlyinto saidsocket, saidskirt'being' disposed around and spaced from,

said bolt portion, and said-primer engaging means comprising a titdisposed on'a forward end of said bolt portion and withinsaid socket,said socket being of a cross sectional size'to loosely accommodatetherein said'rear end of the propellant body; f 7 1 25 7 ReferencesCited in the file of this patent UNITED STATES PATENTS 969,500 1,856,022Blacker Apr. '26, 1932 Pope Oct. 15, 1957 Silva Sept. 6 1910

